System of selective control.



G. E. SGRIBNER, J. L. MQQUARRIB & E. B. CRAFT.

SYSTEM OF SELECTIVE CONTROL.

APPLICATION FILED MAR. 12, 1910.

Pategted Aug. 26, 1913.

3 SHE-ETS-SHEET 1.

C. E. 5 crib/7e r.

J. L. M Qua/fie.

Kfifnesses:

G. B. SGRIBNER, J. L. MoQUARRIE & E. B. CRAFT.

SYSTEM OF SELECTIVE CONTROL. APPLICATION FILED MAR. 12, 1910.

3;,0'71588, Patented Aug. 26, 1913 3 SHEETS-SHEET 2.

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' [.iScr/bner. VI/V/ZCHQSSQSI J L. MOuam'e.

G. E. SCRIBNER, J. L. McQUARRIB-8z E. B. CRAFT.

SYSTEM OF SELECTIVE CONTROL. APPLIOATION HLiD MAR 12,1910.

entrain ras er hilt @lt lii ilfsi.

CHARLES E. SCRIBNER, 0F JERICHU, VEREUE'YT, Afifi JAMES L. MUQUAEEXE, 0FMONT- CLAIR, AND EDWARD B. CRAFT, 9F EACKEHSACK, NEW EEEQQEY; ASSEGNOEST8 WESTERN ELECTRIC COHPANY, OF NEW 3503K, H. Y., A GQR?UE&TIGN 0FILLZNGIS.

SYSTEM 0? EELEGTIYFE GON'EBOL.

specification of Letters Patent.

Patented An 2%, @913.

Application and ism-eh 1s, 1am. 5eris1l'1o. eraser.

T 0 all whom it may concern:

Be it known that ,we, CHARLES E. Scars- Nun, Janus L. h'IOQUARRIE, andEDWARD B. CRAFT, citizens or" the United States, residing at Jericho,Chittenden county, Vermont; lrlontclair, Essex county, New Jersey, and

Hackeusack, Bergen county, New Jersey, re

spectively, have invented a certain new and useful Improvement inSystems of Selective Iontrohof which the following is in full, clear,concise, and exact description.

Our invention relates to systems of selective control and its object isto provide improved means for selectively controlling apparatus at aplurality of stations associated with a line.

Our invention is particularly applicable to selective systems of thegeneral type wherein the switch mechanisms, at the respective stationsof a line, comprise switch members normally movable in definite phaserelationship subject to the control of sending mechanism at a station onthe line, as illustrated, for example, by selective systems of the typeemployed in train despatching. In systems of the type mentioned,heretofore employed, electrou'iotive forces impressed upon the line fromextraneous sourcesmay cause one or more of the switch mechanisms tooperate and advance the corresponding switch members, thereby bringingthe members atthe various stations into some other than their normalphase relationship. Or such extraneous electromotive. forces may operateto advanceall of said members from their normal positions. In eithercase the substation apparatus would be left in other than its normalcondition so that upon a subsequent operation of the sending mechanismthe switchesat the various stations would op crate abnormally, theresult being a confusion of connections.

An important feature of our invention consists in the provision of meanswhereby false operation due to current from an extraneous source isprevented. This is [)I0- videcl for by dividing the movement of theswitch members into two parts, one of which .may be termed thepreliminary range of movement, and preferably consists of but a singlestep, and the other of which may he termed the selective range ofmovement. The switch in our system may be so related l sity of applying9. restoring to the system that it can be advanced through itspreliminary range only by current of one character and can hesubsequently advanced through its selective range only by current of aditlerent character. Vfith this construction current from extraneoussources, whether constant or interrupted, will not advance the switchesat all if it is of one character, and if it is of the other characterwill at most advance them only through their preliminary range. in oursystem means are provided whereby the sending mechanism may send initialcurrent or" one character adapted to advance the switcl'i-es throughtheir preliminary range, after which said mechanism will send currentofa different character ada ted to further advance said switches. hesending mechanism is furthermore provided with means whereby when theswitch members have been advanced to a position corresponding to anygiven station, a current of the same character the initialcurrent, maybe .impressed upon the line to bring a signal or other device intocircuit. This lastmentioned current, by reason of its character togetherwith the fact that the switch members are at this juncture within theirselective range of movement, will have no efiect upon the movement ofthe switlcl'i members.

From the above it will be apparent that in our invention theswitchmembers ifdisturbed atall by extraneous sources of current are moved tobut a slight degree from their normal positions. Also itis obvious thatif the extraneous current is impressed uponthe line at a point where itoperates to advance certain of the switch members only. therebydisturbing the phase relationship of the switch members throughout thesystem, such disturbed phase relationship will be corrected upon theoperation of the sending mechanism prior to the advance of any of theswitch members-through their selective range proper.

In lone lines heavily loaded with substation equipment, the lines of atrain dcspatching system may be, efliciency in the matter of powerconsumption is particularly desirable. By our invention a substationswitch of the type wherein the movable member rotates in a'singledirection may be employed, thereby obviating the nee es orcc to saidmember, the force of which would have to I; mentary be overcome in itsoperation, with consequent consumption of power. Switches of" thisgeneral type are not a part of our in-- vcntion, butt-heir employment isrendered ypracticalby our invention by reason of the feature already setforth whereby, definite phase relationship may be maintained. Other morespecific features of our invention will be hereinafter set forth.

,Our invention will be more readily understood by reference. to theaccompanying drawings, in whichv Figure l is a sender 'mechanism'wh /chmay be used with the system 'of our invention; Fig. 2 is a side view,partly in section, of switch mechanism adapted for use at thesubstations} Fig. 3 is a-fro'nt view ofsaid switchmechanism; Fig. 4 is arear view of said switch mechanism; Fig. 5 is a perspective view partlyinfsection of the switch member and associated 'parts;'-and Fig. 6 is acircuit diagram showing a line equippedin accordance with the system ofour invention, with sending mechanism and two sets of substationequipment. F ig. 7 is a fragsectional view showing details of thesending mechanism.

Like characters of reference are used to designate ,like partsthroughout the several views. t

Referring. to Fig. 1, showing a sender mechanism adapted for use withour system, 7, 8 and 9 are parallel plates spaced in any suitable mannerto form a frame or support 15 for the operating parts. Secured to thelower -face of-the plate 9 are two circular series of radiallyprojecting contact. me

' hers 10 and 11, each of said series being insulated from the other.The contact me mbers comprising each series are, however, in electrical.connection. l2 isa shaft rotatably carried by said plates 7, 8 and 9 andadapted to be driven through one rotation by the sprin actuated gearmechanism 13, 14 and 15, w en the lever 16 is actuated to wind thedriving spring of said mechanism. '17 is a' brush or wiper arm carriedby said shaft 12 and adapted, as it rotates therewith, to normally sweepover-the members 11. of the lowercircular series and make successivecontact therewith. As shown in the drawing, the circular serieslofmembers 10 is mounted in staggered relation to the lower series ofmembers 11. All the members 10,; except the one designated in thedrawing as 1.0, arehowever carried slightly above the members 11,whereby they are normally out of the path of the brush 17. Directly.above th inem bers 10 are keys 18,19,20, 21, etc, onec lreyf foreachsaid member'lO. Each said keyQ' -is slidably carried in. the plates 7, 8and 9 and is adapted, when operated, to depress the correspondingmember. 10, thereby I )ringmg the endef said member intofthe 65 pathsotthe 17 llach, ofsaidkeys comprises a spring member 22, carryiire,- alatch 23 adapted, when said key is depressed, to engage the adjacentedge of the notch 24, within which notch said member 22 is guided. Theend of the. plunger of each key is provided with insulation 25 adaptedto prevent its electrical connection with the member 10. In the drawing,key 19 is shown in its operated position, wherein it is locked asdescribed. The member 10 may be fixedly carried in the path of the brush1? and, for a purpose hereinafter explained, said membernnay be mountedin positionto be engaged by the brush 17 during'its initial movement. Nokey is therefore provided for said member 10. The shaft 12 carries anarm 26 terminating in a member 27 adapted in its rotation to engage withthe projecting end 28 of the spring member 22 of any key which maybedepressed. The arm 26 is so positioned on, the shaft 12 that the brush17 is slightly in advance of the member 27, whereby said brush may makecontact with any member 10 which may be depressed into its path beforesaid member 27 reaches the projec. 'tion 28 of the corresponding key. 29is a plate or contact ring fixedly mounted and 30 is a brushcarri'ed bythe shaft 12 and adapted to'provide an electrical connection of saidplate 29 with the brush 17. 31, 32 and 33 are terminals in permanentelectrical connection with'the members 10, the members. 11 and the ring29,- respectively, as clearly shown in- Fig. 7, In Order to more clearlyshow the construction of the sender,

the shaft and parts carried thereby are not shown in their normalpositions in Fig. 1. Normally the parts mentioned lie in-such :1position that the brush 17 will make contact with the member 10" duringits initial movement. The direction of rotation of the shaft isindicatedby the arrow.

With the construction described, it is apparent that upon turning thelever 16 the driving spring of the gear mechanism willbe wound, therebyresulting in the rotation of the shaft 1.2 and pa'rts carried thereby.The shaft will, during its initial n'iovemcnt, bring the brush 17 intoelectrical connoctimi with member 10 and then successively intoconnection with all the members 11v of the lowercircular series and alsowith any of the members 10 of the upper series which may have beenbrought into its path by the depression of a key. With the relation ofparts as described, it will be obvious that after the brush 17 haspassed a depressed member 10, the member 27 will engage'the end 28 ofthe locking spring of said key, thereby forcing saidend in a radial(iii-cction'and withdrawing the latch 23 from its engagement. withthe-edge of the notch 24, whereby said key will be automaticallyrestored. The mechanism therefore provides 131 respectively.

means whereby a circuit extending from terminal 31- to the ring 29 maybe completed once for each member ll engaged by the brush 17,andwhereby. a circuit extending from terminal 31 to ring 29 may becompleted once for each key depressed, the-latter completions beinginterposed at will be tween any two of the former.

Referring to Figs. 2, 3, at and 5, showing a selector switch adapted foruse with our system, 34 is a frame or mounting comprising the supports35 and 36. An electromagnet comprising coils 37 is secured to support36, said electromagnet being provided with an armature 39 pivotedbetween lu s 4O.

Mounted upon the frame 34 is a U-s raped auxiliary frame 41 comprisingmembers 42 and 43, upon which latter the shaft 44' is rotatably carried.Fixed to the shaft 44 is a ratchet 45 adapted to be actuated by astepping pawl 46 pivotally carried by the arm d7 secured to the armatureThe armature is retracted by spring 48. The stepping pawl is kept inengagement with the ratchet by spring 49. Spring 50 serves a holdingpawl for the ratchet. Referring particularly to Fig. 5, the terminalstructure of the switch comprises supporting plates 51 and 52 betweenwhich are clamped a continuous conducting ring 53, a conducting ring 5which is continuous except for the terminal electrically separatedtherefrom, two adjacent terminals F6 and 57 and members 58., 59 and (30adapted to insulate the members mentioned. The parts referred toconstitute a unit which may be secured to the member 43 of the U-shapedframe il. Projecting from the members 54, 56 and 57 are the connectionterminals (Si, (32, 63, (34 and (3.), Upon the shaft 44 are two sets ofbrushes, one set comprising brushes (38 and 67 adapted, in theirmovement, to connect ring with ring 54 or with terminal 55, and theother set comprising brushes (3% and (39 adapted to connect termi nal 56with terminal 57. The brushes Cl? and 57 are shown in their normalposition in which they connect ring with terminal The brushes (3Sandlit) are carried by a clamp member 70 which in turn is adjustablysecured to the shaft 44 by means of clamping screw 71, whereby saidbrushes may be caused to normally bear any desired angular relation tothe terminals 56 and 57 with which ti 3 engage. With the constructiondescribed, the energization of the elcctromagnet by impulses of currentcauses the advance of the ratchet one step for each impulse, therebycausing the brushes .66 and 67 to more from their normal positioh,wherein they connect ring with terminal 55, to some other position, inany of which other positions they may join ring 53 with ring In theadvance movementof the despatcher. .niechanism, already described, 15located,

ratchet, the brushes G8 and (it) will obviously connect terminal 56 withterminal 57 at some stage of said movement depending upon the angularrelation of said brushes to said-terminals.

Referring to Fig. (5, showing an embodiment of our invention in aselective signaling system, 72 is the sending station which in practicemight be the ottice of a train At said station the sending saidmechanism being so connected in circuit that the brush 17 is inconnection with one limb 73 of the line and the two series of members 10and 11 are, respectively, connected with opposite poles. of batteries 7+and 7 5, the remaining poles of said batteries being connected to theremaining limb 7,6 of the line. The despatchers telephone set 77 may bebridged across the line as shown, impedance coils 78 and 79 beinginserted in the line between the batteries 74 and and said set 77 as ameans of preventing undue disturbance of the telephone of said set byselecting impulses. In the drawing, two way or substations S0 and 81 areshown associated with the line, the apparatus at said stations beingconnected in parallel with the line. The equipment at each station maycomprise, in addition to the selector switch already described, otherswitching mechanism including a polarized relay 82, a locking relay 83,a key 8-1 and a bell, buzzer or other signal 85. The mechanism mayderive its operating power from a battery 86. The armature 87 of thepolarized relay 82 may normally beheld in its mid position by springs 88and 8f) engaging with stops U0 and 91, respectively, whereby current ofone polarity will cause said armature to tilt in one direction and.engage contact 92, and current of the reverse polarity will cause saidarn'iature to tilt in the opposite direction and engage contact 93. Onepole of the battery 86 is connected by conductor 94- with the operatingmagnet 37 and thence, through conductor 95, with the ring of the switch,Wllhl'QHl'lOfl twoparallel paths to the polarized relay 82 are provided.one of which paths is completed by brushes (36 and ($7 in their normalposition as shown in the drawings, whereby the circuit thus partiallytraced is extended from ring 53 through said brushes to terminal 55,thence through conductor 96 to normally open contact 92 of relay 82,thence through armature 87 and conductor .97 tothe battery 86 In thenormal position of-the brushes 6 and (37, the circuit just tracedthrough the 0pcrating magnet 37 will therefore be completed by thepolarizedrelay 82 when said relay is energized by current of suchpolarity to cause its armature to tilt in a clockwise direction and inno other position of said brushes will. said electromagnet 37 l dd beoperated by such operation of the polar ized relay 82. The remainingparallel return path for the circuit through the operating'electroma'gnct is from ring 53 through brushes and (37, conductor 98,normally open Contact 03, armature S7 and conductor 97 to the battery.This circuit is normally open and can therefore only be completed by thepolarized relay when the brushes 66 and (37 are in some other thannormal position. The operating electromagnet may therefore be ema-gizcdby the completion of either of the above described circuits andtherefore may be energized by current of either polarity throughtherelay 82. It'will be observed, however, that each of the localoperating circuits is subject to both the selector switch and thepolarized relay and can be completed only under certain conditions withrespect to both the polarity of the line current through the relay82 andthe position occupied by the 07 at theinstant in question and that saidthat with the normal positions, said brushescannot be condition may besuch that at no time will the energization of the relay 82 by current ofother. than one polarity result in the operation of the electromagnet\Vith the arrangement described, it will be apparent brushes (36 and (37in their caused to move more than a predetermined distancefrom normal bysuccessive line im after having termiued polarity.

pulses, and that even this movement is possible only when the linecurrent is of predestructure is such that said predetermined distance islimited to one step.

Referring to the circuit controlled by the switching mechanism, acircuit is shown including a signal 8-"). This circuit is shown asextending from battery 86 through conductor 99,-s'ignal 85, normallyopen terminals 56 and 57, conductor 100, conductor 96, normally opencontact 92, armature 87 of relay 82, and conductor 9'? to the other poleof the battery 86. In parallel with the signal, 85,- a locking relay 83may be provided, whereby when the circuit of the'bell is completed, thatofthe relay is also. The locking circuit of the relay 83 extends frombattery-86 through conductor 99, conductor Tn the drawings the brushes66 and 101, the winding of said rclay 83, locking contact 102 andarmature 103 of said relay maining pole of the battery. \Vith thestructure described, the brushes 68 and 69,

been moved the required number of steps from normal, willengage withterminals 56 and 57 and thereby prepare the circuits of the-signal 83for completion by the polarized relay 82, which latter relay willrespond to a current of proper polarity to tilt its armature in aclockwise direction: and, thereby com- 83, key 84 through conductor 105,to the re- 85 and relay plete said circuits. It will be observed thatunder the conditions existing at this junclure, the'operation of thepolarized relay in a clockwise direction produces no effect upon theother circuits. The circuits of the buzzer and lockingrelay havlng. beencompleted as described Wlll remain complete tl1r-: ugh the lockingcircuit, already traced,

until key 84 is operated to open said circuits. Obviously, except forthe locking means, the, hell would operate only during such time as thebrushes 68 and 69 remained upon terminals 56 and 57. Under certainconditions this, however, might'be sufficient. Itwillbe understood thatin the switches at -the respective stations, thebrushes 68 and theoperator at sending sta .ion 72 wishes to signal station 81 and that inthe switch at said. station the brushes (8 and 69 are so placed withrespect to brushes 66 and (37 that threesteps are required to bring theformer into engagement with terminals 56 and 57 The operator at thesending station will depress that .key of the sender which will bring amember 10 into the path of the brush 17 between the second and third ofthe members 11. Upon turning the lever 16 in a direction to wind thedriving spring and then releasing the same, the shaft 12 will rotatethrough one complete rotation, the brush 17 first engaging member 10',whereupon battery 74 is connected with the line, thereby resulting inthe operation in a clockwise direction of the polarized relays 82' atall stations. The operation of said polarized relays causes thecompletion of tions, whereby the switch brushes are advanced one step.The sender brush having passed member 10 next engages two members 11 insuccession, whereby battery 75 is momentarily connected with the linetwice. As a result, two impulses of current of such polarity as tooperate the polarized relays 82 in a counterclockwise direction areimpressed upon the line. The. operation of the polarized relays twiceasgdescribed advances the brushes at all stations two steps, whereuponbrushes 68 and 69 of station 81 are brought into engagement withterminals 56 and 57, thereby preparing the circuits of the signal 85 andlooking relay 83 for completion by a r of polarizedrelay 82. Thisreversed operation is provided for by the key referred operatingelectromagnets 37 at all stah versed operation to above as having beendepressed, whereby the brush 17 coming in contact with the memberdepressed by said key,'connects battery 74 with the-line, therebymomentarily com hating the circuit of the bell and locking re y atstation 81. Said circuit .will, as already explained, be locked sub-}ect to. the Operation of key 84. The bell and locking circuit will ofcourse be completed by the impulse under consideration only atstation.81 by'reason of the fa'c't'that at this station-only arethe'brushes 68 and i 69- in contact with terminals 56 and 57 at withoutaffecting others.

this juncture.

From-the above it will be readily understood that if impulses of currentof one polarity be impressed upon the line, said impulses will v operateeach of the switches through its preliminary range only, whichpreliminary range, in the system shown herein, comprises but one step,although not necessarily so limited. Furthermore, said impulses may beof either polarity without advancing the-switches through more than saidpreliminary range. They may, more over, act upon part of the. circuitonly whereby they might advance certain of the switches through theirpreliminary range This, however,

' would not result in false signaling by reason of the fact that thesender is provided with one or more members 10', whereby said senderimpresses one or more preliminary impulses upon the line during itsinitial operation, the number depending upon the extent of saidpreliminary range, and therefore would bring any displaced switches intov proper phase relationship before actuating all of the switches.

lVhile we have described a form of our invention in which a current ofone polarity is adapted to. control the movement of the switch membersthrough the preliminaryrange and a current of a reverse polarity isadapted to move such switch members I comprising a member havmgapreliminary through their selective range, it must be understood thatour invention isnot limited. .to the use of a polarized relay nor to theuse anism at each of a plurality of stations on said line, said switchmechanism .being adapted to be advanced througha preliminaryrange ofmovement under control of fiirrent of one character and through afurther rangeunder control of current of an:

other character, and means cooperating with 2. The combination with aline, of a source of cprrent at a station on said line, sending mecanism for impressing positive and negative current upon said line,switch mechanism at each of a plurality of stations on. said line, saidswitch mechanism being adapted to be advanced through a preliminaryrange of movement under control of current of one polarity and througha'further range under control of impulses of reversed polarity, andmeans c'oiiperating with said switch mechanism for preventing theadvance of said switch through more than said preliminary range undercontrol of successive impulses of either one polarity alone.

3. The combination with a line, of a source of current at a station onsaid line, sending mechanism for'impressing currents of differentcharacter upon said line, switch mechanism at a plurality of stations onsaid line controlled by currents of different character, said switchmechanism comprising a member having a mechanism comprising a memberhaving a preliminary range of movement and a selective range ofmovement, and means cooperating with said switch mechanism wherebycurrent of one character adapted to control movement of said memberthrough. one range will beinefi'ective for controlling'movement throughsaid second range.

4. The combination with a line',of asource of current at a stationonsaid line, sending mechanism for impressingpositive and negative currentupon said line, switch mechanism at each of a plurality of stations onsaid line controlled by said positive and negative current, said switchmechanism range of movement and a selective range-of movement, and meanscoiiperating with said switch mechanism whereby current of polarityadapted. to control the movement of said member through one range willbe ineffective in controlling the movement through said second range. I

The combination with a line, of a' source of current at astation' on sad line,

sending mechanism for impressing impulses of current of differentcharacter upon said line, and a selector switch mechanism com prising amovable member, at each' of a plurality of stations on said line, said.switch mechanism being adapted in a selecting operation to advance inresponse 'to initial current of one character and subsequently inresponse to current of another character only; 4 v

tii'lhe combination'with a line, of a source-of current at a station onsaid line,

h'tflldlllg' mechanism for impressingpositive and negative impulsesof'current upon said line, and selector switch mechanism comprising amovable member at each'of a plurality ofstations on said line, saidswitch mechanism being adapted in a selecting op eration to advance inresponse to initial current of one polarity and subsequently, inresponseto current of reversed polarity only.

7. The combination with a line, of a source of current at a station onsaid line,

sending mechanism fouimpressing positive and negative current upon saidline, mechanism comprisinga movable switch member at each of a pluralityof stations on said line; a circuitcontrolled by said member at apredetermined position, said mechanism operating in response to currentof one po-' larity to cause the initial advance of said member and inresponse to current of reversedpolarity only tocause the subsequent Iadvance of said member tosaid position.

8. The. combination with a line, of a source of current ,at a station onsaid-line, sending mechanism for impressing positive and negativecurrent upon said line, mechanism comprising a movable switch member ateach ofa plurality ofstations on saidline, a circuit controlled ,by saidmember at a predetermincdposition, said mechanism operating in responseto current of a given 110- larity to causethe initial movement of saidmember, in response to current of reversed polarity only to cause thesubsequent movement of said member, and .in response to current of saidgiven polarity to controlsaid circuit.

1). The combination with a line, of. a sourcc'of current at a station'on said line, sending mechanism for impressing positive and negativecurrent upon said line, mechanism comprising a movable switchmember ateach of a pluralit" of stations on said line, a circuit controlled ysaid memberat a predetermined position, a signal controlled bysaidcircuit, said mechanism operating in respouse to .currentof a givenpolarity to cause the initial movement of said member,

in response to current of reversed polarity only' to cause thesubseq'uent'movement of said member, and in response to current of saidgiven polarity to control said circuit.

10. The combination with a line, of a. source of current ata station onsaid line, sending mechanism for-impressing positive and negativecurrent upon said line, mechanism comprisin ateach .of' a p firalityofstat-ions on said line, a circuit controlled by said member at apredetermined position, a relay controlled by said circiiit, and asignal controlled by said relay, said mechanism operat'ing in responseto'eurrent of a g ven polarity to a movable switch member cause theinitial movement ofsaid member,

cal to cause the subsequent movement of in response to'cnrrent of;reversed polarity,-

sai member, and in response to current of said given polarity to'controlsaid signal.

' 11. The combination with a line, of a.

source of current at a station on saidline, sending mechanism forimpressing; ost

tive and negative 'currentu pna sa lline,

a polarized relay atgeach 6f a pl iality of stations on said line,'aswitch at'each 'of said 12. In. a selective. signaling system, the

combination with a line having a sendingstation and a. plurality of waystations con- .nected therewith, of-mechanis n at said sending stationfor lmpressin ferent character upon said line s. Step1 step selectivedevice at each of said waytations embracing an electromagnet,unopcrating circuit for said electr'omagnct havng two branches, anda,c'ircuit closing .de-- vice connected with the line at' each of saidway stations and operated by the currents of different character oversaid line to close the two branches of said operating circuirespectively.

13. In a selective signaling systcln,-the

combination with a line having a sending station and a plurality ofwaystations connected therewith, of mechanism at saidsending station forimpressing currents of-different character. upon said line, astep-bystep'selective device at each of said way stations embracing anelectromagnet, an operatingcircuit for said electromagnet having twobranches, and a polarized relay connected with the line at each of saidway stations adapted in response to current of one characterto close onebranch of said operateurrents of difing circuit and in response tocurrents of another character to close the other branch of saidoperating circuit. I

14.- In a selective signalin system, the combination'wi'th a line he gasending station andaplurality of way stations connected therewith, ofmechanism at said sending station for impressing currents of differentcharacter upon said line, a step-bystep selective device at each of saidwe s'ta tions, a switching device at each of sai wav stationsresponsiveto the currents of dii ferent character impressed upon theline at the sending station, and an operating circuit for said selectivedevice having two bran hes each jointly controlled by said switchingdevice and said selective device.

15. In a selective signaling system, the combination with a line havinga sending station and a plurality of way stations. connected therewith,of mechanism at said sending station for impressing currents of dif'ferent character upon the line, a step-bystep selective device embracingan electromagnet and a movable member at each of said way stations, acircuit closing device connected with the line at each of the waystations responsive to the difl'erent character currents impressed uponthe line at the sending station, and an operating circuit for saidelectromagnet embracing two branches one of'which is closed when .themovable member thereof is in one/position and current of one characteris sent over the line, and the other branch of which is closed when themovable member thereof is in another position and current of anothercharacter, is sent over the line.

16. In a selective signaling system, the combination with a line havinga sending station and a plurality of way. stations con nected therewith,of mechanismat said sending station for impressing currents of'different character upon'the line, a step-bye step selective device,embracing an electro-, ,magnet. a movable member and circuit closingcontacts controlled by said movable member, located at each of said waystations, a polarized circuitclosing device connected with the line ateach of said way stations and responsive to the currents of differentcharacterimpressed upon the line at the sending station, and anoperating circuit for said electromagnet comprising two branches one ofwhich is closed only when the movable member thereof is in a givenposition and current of one character is sent over the line and theother of which is closed when said movable member is in other than thefirst mentioned position and current of a different character is sentover the line.

17. The combination with a line, of a sponse to current of one characterto com-" plete one of said brancheswhen the switch is in its normalposition and operate in response to current of another character tocomplete the other of. said'branches when the switch is in other thanits normal position, and a second cir-uit jointly controlll by saidswitch and relay at a predetermined point in the advance movement ofsaid switch.

18. The combination with a line, of a source of current at a station onsaid line, sending mechanism for impressing positive and negativecurrent upon said line, an electromagnetically controlled switch at eachof a plurality of stations on'said line, an actuating circuit for saidswitch comprising two branches, said branches being alternately renderedoperative during the operation of the switch, a polarized relay adaptedto 0perate in response to current of one polarity to complete one ofsaidbranches when the switch is in its normal position and to 0perate inresponse to current of the reversed polarity to complete the other ofsaid branches when the switch is in other than its normal position, anda second circuit controlled jointly by .said switch and relay at apredeterminedpoint in the advance movement of said switch.

In witness whereof. we hereunto subscribe our names this -11th day ofMarch A. 1).,

CHARLES E. SCRIBNER. JAMES L. MGQUARRIE. EDWARD B. CRAFT. WitnessesIavnvc MAQDONALD, MORGAN VVAsHBURN, Jr.

